


Positive Reinforcement

by FrameTrap



Category: Fire Emblem Series, Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Breast Expansion, Breast Fucking, Cock Shock, F/M, Female My Unit | Byleth, Huge Breasts, Paizuri, Reader-Insert, Teacher-Student Relationship, huge penis, male reader - Freeform, reader POV
Language: English
Status: Completed
Published: 2019-08-16
Updated: 2019-08-16
Packaged: 2020-09-01 07:48:15
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 1,673
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20254681
Author URL: https://archiveofourown.org/users/FrameTrap/pseuds/FrameTrap
Summary: Byleth has a special reward for her star student.





	Positive Reinforcement

It had been innocuous enough. Byleth just simply asked you to meet up with her after your classes were over, to see her after class. Byleth asked it with as much stoic seriousness as she said anything else, nothing was amiss.

Things had, evidently, taken a much different turn than what you were expecting, as Byleth gripped her hands around your wrists, and with shocking strength despite outsizing her, she shoved you back and laid you out on top of her cleared desk, causing a quick grunt to escape your lips as she forced you down onto your back.

You're undeniably concerned, and your mind wanders, trying to come up with something, anything you did to have pissed her off this much. You look into her eyes as she does yours, her gaze unwavering and just as neutral as it has always been. You part your lips to speak. "Stay quiet." She commands, and of course, you listen. Though regardless, your body is still nervous, and moves around underneath her weight. It’s difficult enough to move as she pins you down only from gripping your arms, but the task becomes one of great impossibility as you’re weighed down upon by her expansive and heavy breasts.

The most curious part of Ms. Byleth, by all accounts, was how her breasts would seemingly grow constantly. Even today you noticed that she was noticeably bigger than the day before, and that fact only became more apparent as you felt her outrageously sized tits pressed up against you, squishing up against your waist. Hyper-aware of the sensation, a pressure wells up in your chest as your body quivers as your crotch is pinned down underneath her, the softness of her chest rolling around and pressing down on it as you struggle underneath her.

She pushes down harder onto you, mashing more and more of the weight of her tits down where you’re most sensitive, as she plants your arms down onto the desk. “Don’t move.” she says again, direct and calculated to make you do just as she says. When she’s sure you’ve stopped resisting, she releases her grip on your wrists and moves her hands back, sliding them underneath her breasts. “In case you haven’t figured it out yet, this is part of my new program for rewarding students. You’ve been at the top of the class since the year began, so it only makes sense for you to get your reward first.” You stare deep into the crevice of her cleavage, still bundled up in her shirt, as you feel her hands work over your pants, unbuttoning and unzipping them. Her breasts appear to jump slightly as your developing hardon eagerly springs up from its confines. Your heartbeat races ever faster as you experience the feeling of her fingers wrapping over the hem of your underwear and pulling them off of you. A small, muffled rush of air escapes her as she felt your hot erection smack against the soft, sensitive skin of her tits. Her position on top of you provided the perfect path for your cock to travel, as she guided it to slide neatly into her cleavage. She appeared to marvel at it, a slight glint in her eye appearing as she awed at its size, her stoicness broken into a look of true surprise and shock. “You’re very big… Bigger than anyone I’ve ever seen before.” You could’ve sworn you saw the slightest curve of a smile form from her lips as her eyes’ lids dropped back down to their normal position, before her hands wrapped around the sides of her breasts. The overwhelming anticipation built up within your loins over the preceding few, agonizing moments was paid off in full and more as you felt her breasts begin to move, stroking the sides of your erect cock, their softness enveloping and squeezing you with unmatched warmth and pressure.

You feel the warmth of her breasts, slick with sweat, and gaze upon them, seeing the folds of her shirt as Byleth’s nipples erected and poked at their cloth prison. “You’re really a special one, aren’t you?” She mused as she gazed upon the head of your cock as it bobbed up and down with the movement of her breasts as, surprisingly enough, it poked out of the cleavage of her breasts. Although her face didn’t show a hint of it, it was evident that this was turning her on.

This moment, this experience left your body shuddering with a feeling of relief, but also a desire for more. Byleth had been the target of your unbridled lust for a painfully long time by now, the way her regular outfit looked like it’d fit better on a stripper than a teacher, how hugged her perfect curves in an equally perfect way, and not to mention how it tried to fight and eventually lost against her mystifying, ever-expanding mammaries that made your eyes bug out of your head when you first saw them get bigger. Truly, a frustration had been mounting,  _ building _ itself up within you, not helped at all by your wild hormones, and now it was finally able to release itself over the woman of your dreams.

Moving your hands to her breasts, you place them over hers and move them in tandem as you begin to buck your hips. Slowly at first, they rise and fall, pushing your erection up through the valley of titflesh and thrust up out through the other side, thick globs of precum spurting from the tip and lubricating her chest. Soon though, you begin to rock your hips faster, faster,  _ faster _ until you’re humping her tits like a wild animal, sending the wisps of your essence everywhere all around the scene, spattering against your torso, her breasts and face, and even the table you laid upon.

“That’s it…” She said, the breathy words escaping from her lips. “This is  _ your _ reward, make the most of it and use me,  _ fuck _ my tits like the beast you are.” The sensual words of Byleth were punctuated as she began to flick her tongue along your length and moved one of her hands to fondle your large, full balls, urging them to produce more semen just to shoot all over her as you continue fucking her tits with abandon. You hear her coo as your dick  _ throbs _ between her tits, your pulsing veins beating with every pump of your racing heart.

Suddenly, Byleth hands land on top of your own, clasping them into her grasp, pressing them deep into her breasts, before beginning to  _ slam _ them down onto your crotch, sliding her warm, wet breasts across your monstrous length with a speed unattainable on your own. Vocalizations of indescribable, immense pleasure escape your voice as you’re left a trembling mess under her violently fast titfuck. Despite this, your hips don’t stop, and she lets out a hushed, breathy moan as your thrusts reach a fever pitch, slamming your length through the valley of pillowy soft cleavage at a speed matching her own skillful movement of her gargantuan tits. “You’re trying to hold it in, aren’t you? That won’t do you any good, why don’t you just let it out, it’ll be a lot better for you.” She breathes out just as your balls tightened up, signaling your nearing climax.

Such encouragement from her soft, sultry voice is unable to be denied or ignored. You  _ explode _ , your balls pulsing and your hips seizing in place, your tip buried in-between her tits, as you begin firing off shot upon shot of hot, sticky semen into the never-ending valley between her two perfect globes. Your legs tremble, shake, and spasm as you feel her squish down harder onto her breasts, the pressure on your head compounding even further as your backed-up load empties itself, erupting from her cleavage with enough force to send a shot of your seed flying high into the air, one which curves back down to return to Byleth’s chest once more. Jizz begins leaking from the bottom of her cleavage and squeezed out from the top on account of your cock working overtime to cum more than you ever have in your entire life.

“I’m assuming you’re satisfied with your reward?” Byleth inquires rhetorically as she gazes upon your exhausted, satisfied face as you stare up at the ceiling, feeling utterly drained. You lock up briefly as Byleth pulls her breasts off of your cock, a string of cum following your drenched tip as its removed from her own similarly drenched cleavage. “I guess I wasn’t wrong about calling you special. You nearly covered my entire chest.” Byleth mused. You pulled your head up, looking upon her as her breasts, chest, and face were plastered in your essence. The sight of your own teacher, the one you have lusted for months over, covered so totally by your own cum is enough to send you over the edge again, your cock rising high again, as though you hadn’t just unloaded the same amount as ten men would upon her.

Byleth’s eyes flicker upon your tireless erection and then narrow. “Seems like it was too soon to say you were satisfied. However…” Byleth leans over to you once more, lifting her breasts above your cock again, ready to plunge them down onto you and repeat the process just completed…

...Only for her tits to grow right before your eyes. The two flawless breasts, which your normal brain couldn’t have ever imagined would get bigger, grew once more. One cup size, then two, then three, four, five… If you weren’t already dazed you would’ve realized they damn near doubled-- no,  _ tripled _ in size, to the point where they even dwarfed your immense cock, shrouding it in the shadow of her breasts.

“I have just the tools to solve this problem…” Byleth said, with her stoic, almost bored expression unwavering but a noticeable glint shining in her eye.

You realize only now just how outmatched by your professor you truly are.


End file.
